An art of retrieving an unknown music piece similar to user's favorite music piece is disclosed in Japanese Patent Publication No. 2004-46575 (refer to Patent Reference 1).
Another art of retrieving a music pieces in tune with user's taste more appropriately from among a lot of music pieces is disclosed in Japanese Patent Publication No. 2005-18205 (Patent Reference 2).
Another art is disclosed in Japanese Patent Publication No. 2005-276400 (Patent Reference 3), with regard to a music contents playing apparatus in which music is automatically selected and played successively to prevent users from being bored even after repeatedly used.
Furthermore, an art of retrieving information on a music which is currently played around, such as title of the music, player's name and so on using a mobile terminal is disclosed in Japanese Patent Publication No. 2002-215632 (Patent Reference 4).
Also, conventionally, unknown artists can be searched through many music artists in such a manner as reading recommendation information of the music artist or having a view of a similar music artist through amazon.com or allmusic.com to search for a desired music artist.    [Patent Reference 1] Japanese Patent Publication No. 2004-46575    [Patent Reference 2] Japanese Patent Publication No. 2005-18205    [Patent Reference 3] Japanese Patent Publication No. 2005-276400    [Patent Reference 4] Japanese Patent Publication No. 2002-215632